Researchers say each new calf spotted this year is an encouraging sign for the critically endangered whales. No newborns were spotted during the last calving season, and just five calves were counted during the previous year.

But Katie Jackson of the Florida Fish and Wildlife Conservation Commission tells The Daytona Beach News-Journal that seven calves “still isn’t enough.” The wildlife biologist says right whales need to deliver 16 to 18 calves a year just to maintain their current population.